In a medium bowl, combine flour, sugar, baking powder and salt. In another bowl, beat egg whites, applesauce and milk. Add to dry ingredients. Pour into a 9-in. square baking pan that has been coated with cooking spray. Combine topping ingredients; sprinkle over batter. Bake at 375° for 25 minutes or until a toothpick inserted in the center comes out clean. Serve warm.